2021 №01 (06) DOI of Article
2021 №01 (02)

Technical Diagnostics and Non-Destructive Testing 2021 #01
Technical Diagnostics and Non-Destructive Testing #1, 2021, pp. 3-10

Eddy current monitoring of aluminum alloy degradation during long-term operation of aircraft

V.M. Uchanin1, O.P. Ostash1, S.A. Bychkov2, O.I. Semenets2, V.Ya. Derecha2
1G.V. Karpenko Physico-Mechanical Institute of NASU. 5 Naukova str., 79060, Lviv, Ukraine. E-mail: vuchanin@gmail.com
2Antonov Company. 1 Akademika Tupoleva str., 03062, Kyiv, Ukraine. E-mail: info@antonov.com

The monitoring of aluminum alloy degradation is a very important part in aging aircraft maintenance strategy. Our approach is based on the possibility to fi nd the correlation between the material parameters measurable nondestructively and cyclic crack growth resistance characteristics of evaluated material. It was revealed that specifi c electric conductivity as a structure-sensitive parameter of aluminum alloys measured by eddy current method, can be applied as effective tool for such evaluation. The main advantage of the eddy current method is the possibility to carry out the measurements without direct contact with the inspected surface. From the eddy current method point of view, the aircraft component can be represented by 3 layer object which consists of dielectric protective coating, anticorrosive layer about 0,5 mm thick of pure aluminum cladding and aluminum alloy skin subjected to operational loading. To measure conductivity in this third layer with high lift-off suppression (up to 0.5 mm) a new eddy current conductivity meter of the VEPR-31 type was developed. The correlations between the elongation, fatigue limit and electrical conductivity of degraded D16Т and B95Т1 alloys for different equivalent stresses were obtained. The EC electrical conductivity measurements carried out in real aircraft repair plant conditions in Antonov-12B aircraft (produced in 1966) after long-term service confi rmed the proposed methodology effi ciency. Ref. 27, Fig. 8.
Keywords: aircraft, aluminum alloys, degradation, eddy current method, electrical conductivity, fatigue crack growth resistance

Received: 22.01.2021


1. McMaster, R.C., McIntire, P. (1986) Nondestructive Testing Handbook. Vol. 4: Electromagnetic testing (Eddy current, flux leakage and microwave nondestructive testing). USA, American Society for NDT.
2. Dorofeev, A.L., Kazamanov, Yu.G. (1980) Electromagnetic testing. Moscow, Mashinostroenie [in Russian].
3. Uchanin, V.M. (2006) Eddy current testing of structure elements. Fiz.-Khim. Mekhanika Materialiv, 4, 66-73 [in Ukrainian]. https://doi.org/10.1007/s11003-006-0106-5
4. Dobmann, G., Boller, Ch., Herrmann, H.-G. Altpeter, I. (2014) Micromagnetic and electromagnetic NDT for lifetime management by monitoring ageing of structural materials. Int. J. Microstructure and Materials Properties, 9(3-5), 348- 359. https://doi.org/10.1504/IJMMP.2014.066915
5. Estorff, U., Davies, L., Trampus, P. Eds. (1999) In: Proc. of the Joint EC-IAEA Meeting on NDT methods for monitoring degradation, Petten, European Commission, JRC Institute of Advanced Materials.
6. Ostash, O.P., Fedirko, V.M., Uchanin, V.M. et al. (2007) Fracture mechanics and strength of materials. Vol.9: Strength and fatigue life of aircraft materials and structure elements. Lviv, Spolom [in Ukrainian].
7. Ostash, O.P., Andrejko, I.M., Golovatyuk, Yu.V. (2006) Degradation of materials and fatigue strength of aircraft structures in long-term operation. Fiz.-Khim. Mekhanika Materialiv, 4, 5-16 [in Ukrainian]. https://doi.org/10.1007/s11003-006-0098-1
8. Nesterenko, G.I., Basov, V.N., Nesterenko, B.G., Petrusenko, V.G. (2006) Influence of long-term service of aircraft on properties of materials of their structures. Problemy Mashinostroeniya i Nadyozhnost Mashin, 4, 41-50 [in Russian].
9. Ostash, O.P., Kiva, D.S., Uchanin, V.M. et al. (2012) Diagnostics of technical condition of aircraft structures after longterm operation. Tekh. Diagnost. i Nerazrush. Kontrol, 2, 15- 22 [in Russian].
10. Ostash, O., Uchanin, V., Semenets, O., Holovatyuk, Y., Kovalchuk, L., Derecha, V. (2018) Evaluation of aluminium alloys degradation in aging aircraft. Reseach in Nondestructive Evaluation, 29(3),156-166. https://doi.org/10.1080/09349847.2017.1302622
11. Uchanin, V., Ostash, O. (2019) Development of electromagnetic NDT methods for structural integrity assessment. Procedia Structural Integrity, 16, 192-197. https://doi.org/10.1016/j.prostr.2019.07.040
12. Uchanin, V., Ostash, O., Nardoni, G., Solomakha, R. (2020) Coercive force measurements for structural health monitoring. In: The Fundamentals of Structural Integrity and Failure. Ed. by Richard M. Wilcox. New York, Nova Science Publishers.
13. Uchanin, V.M., Ostash, O.P. (2019) Evaluation of operational degradation of structural materials by electromagnetic methods of nondestructive testing. In: Proc. of 9th Nat. Sci.- Techn. Conf. on Nondestructive Testing and Technical Diagnostics (Kyiv, 21.11.2019), 35-40 [in Ukrainian].
14. Uchanin, V.M., Rybachuk,V.G., Kulynych, Ya.P. Eddy current method for measurement of parameters of electrical conductivity anisotropy of nonferromagnetic materials. Pat. 138680, Ukraine, Int. Cl. G01 N27/90. Publ. 10.12.2019
15. Dorofeev, A.L., Ershov, P.E. (1985) Physical fundamentals of electromagnetic structuroscopy. Novosibirsk, Nauka [in Russian].
16. Naumov, N.M., Miklyaev, P.G. (1974) Resistometric nondestructive testing of aluminium wrought alloys. Moscow, Metallurgiya [in Russian].
17. Rummel, W.D. (1966) Characterization and evaluation of 2014 aluminum alloy by eddy current conductivity techniques. Materials Evaluation, 14(6), 322-326.
18. Bakunov, A.S. (2004) Evolution of equipment for eddy current structuroscopy of nonferrous metals in Russia. Kontrol. Diagnostika, 4, 63-64 [in Russian].
19. Nazarchuk, Z.T., Uchanin, V.M., Kulynych, Ya.P. (2019) Optimization of eddy current testing parameters of degradation changes in specifi c conductivity of aluminium alloys of aging aircraft. Vidbir i Obrobka Informatsii, 47, 5-11 [in Ukrainian]. https://doi.org/10.15407/vidbir2019.47.005
20. Uchanin, V.N., Makarov, G.N. (1996) Suppression of influence of gap in contactless measurement of specifi c conductivity by eddy current method. Tekh. Diagnost. i Nerazrush. Kontrol, 4, 41-45 [in Russian].
21. Uchanin, V.M. (2012) Method for measurement of electrical conductivity of nonmagnetic materials. Pat. 98206, Ukraine. Publ. 25.04.2012 [in Ukrainian].
22. Uchanin, V.M., Cherlenevskyi, V.V. (2011) Device for eddy current testing of parameters of products. Pat. 58670, Ukraine. Publ. 26.04.2011 [in Ukrainian].
23. Uchanin, V.M., Makarov, G.M. Cherlenevskyi, V.V. (2012) Eddy current specifi c conductivity meter of nonferromagnetic materials. Pat. 97304, Ukraine. Publ. 10.01.2012 [in Ukrainian].
24. Ostash, O.P., Andrejko, I.M., Markashova, L.I. et al. (2013) Influence of long-term operation on structure and physicomechanical properties of aluminium alloys of D16 and V95 type. Fiz.-Khim. Mekhanika Materialiv, 49(1), 18-27 [in Ukrainian]. https://doi.org/10.1007/s11003-013-9578-2
25. Ostash, O.P., Uchanin, V.M., Andrejko, I.M., Golovatyuk, Yu.V. (2013) Eddy current method for determination of operation degradation degree of structural materials. Pat. 101424, Int. Cl. G01N27/90. Publ. 25.03.2013 [in Ukrainian].
26. Ostash, O.P., Uchanin, V.M., Andrejko, I.M., Golovatyuk, Yu.V., Kovalchuk, L.B. Eddy current method of determination of local degradation degree of structural materials during long-term operation. Pat. 106168, Ukraine, Int. Cl. G01N27/90. Publ. 12.05.2014 [in Ukrainian].
27. Ostash, O.P., Uchanin, V.M., Semenets, O.I., Golovatyuk, Yu.V., Kovalchuk, L.B., Derecha, V.Ya. (2017) Method of monitoring of local degradation degree of materials of aircraft structures in long-term operation. Pat. 113736, Ukraine, Int. Cl. G01N27/90. Publ. 10.02.2017 [in Ukrainian].

Advertising in this issue: